Modem interface device

Abstract

An apparatus for connecting a telecommunications device, such as a computer or facsimile machine modem, to a telephone line via a telephone set. The telephone set includes a base and a handset connected to the base by a handset cord. The handset cord has at one end a handset plug and the base has a base jack for receiving the handset plug. The apparatus selectively electrically couples one of the handset and the telecommunications device to the base. The apparatus includes a first plug for electrically coupling with the base jack, a first jack for electrically coupling with the handset plug, and the second jack for electrically coupling with the telecommunications device connecting plug. A switch, manually selectable between a first position and a second position, electrically couples the first plug with the first jack when in the first position. A converter is coupled to the switch and the second jack such that when the switch second position is selected, the switch electrically interfacing the first plug with the second jack.

I claim: 
     
       1. An apparatus for connecting a telecommunication device having a connecting plug to a telephone line via a telephone set having a base and a handset connected to said base by a handset cord wherein said handset cord has at one end a handset plug and said base has a base jack for receiving said handset plug wherein said telephone base has a pair of base microphone lines and a pair of base speaker lines connected to said base jack and said handset has a pair of handset microphone lines and a pair of handset speaker lines connected to said handset plug, said apparatus for selectively electrically coupling at least one of said handset and said telecommunications device to said base wherein said telecommunications device has a pair of communications lines connected to said connecting plug, said apparatus comprising: first plug means for mating and electrically coupling with said pair of base microphone lines and said pair of handset speaker lines at said base jack;   first jack means for receiving and electrically coupling with said pair of handset microphone lines and said pair of handset speaker lines at said handset plug;   second jack means for receiving and electrically coupling with said communications lines at said connecting plug;   switch means manually selectable between a first position and a second position for electrically coupling said first plug means with said first jack means when in a first position so as to couple each base microphone line with a corresponding handset microphone line and couple each base speaker line with a corresponding handset speaker line; and   converter means electrically coupled to said switch means, said first plug means and said second jack means for, when said switch means is in said second position, electrically coupling said first plug means with said second jack means so as to directly couple each base microphone line with a corresponding communication line and electromagnetically couple each base speaker line with a corresponding communication line with said pair of base microphone lines and said pair of base speaker lines electrically isolated with respect to each other.   
     
     
       2. The apparatus of claim 1 further comprising signal level selector means coupled to said converter means for, when said switch means is in said second position, providing a selected resistance between said converter means and said first plug means. 
     
     
       3. The apparatus of claim 1 further comprising current source means coupled between said converter means and said second jack for providing a current to said second jack. 
     
     
       4. The apparatus of claim 1 wherein said converter means comprises a transformer having primary and secondary windings, each end of said primary winding connected to said second jack means for coupling with a respective one of said communications lines, said primary winding having a tap connected to said first jack for connecting to one of said handset speaker lines and connected to said first plug means for connecting to one of said base speaker lines, one end of said primary winding connected to said first plug means for connecting to the other one of said base speaker lines and said switch means, one end of said secondary winding connected to said switch means, and the other end of said secondary winding also connected to said switch means, said switch means connected to said first plug means for connection with said switch means one and an other one of said base microphone lines, and said switch means connected to said first jack means for connection with said switch means one and an other one of said handset microphone lines and another one of said handset speaker lines said switch means when in said first position for, coupling said first plug means to said first jack means to connect said one of said base microphone lines to said one of said handset microphone lines, said other one of said base speaker lines to said other one of said handset speaker lines, said other one of said base microphone lines to said other one of said handset microphone lines, and said switch means when in said second position for coupling said first plug means to said second jack means, to connect said secondary winding other end to said one of said base microphone lines, and said secondary winding one end to said other one of said base microphone lines. 
     
     
       5. The apparatus of claim 4 further comprising signal level selector means disposed between said switch means and said secondary winding one end for selectively electrically resistively coupling said first plug means connection of said other one of said base microphone lines to said secondary winding one end. 
     
     
       6. The apparatus of claim 4 further comprising polarity switch means coupled to said primary winding and said first plug means connection of said other one of said base speaker lines for coupling said first plug connection of said other one of said base speaker lines to a selected primary winding end. 
     
     
       7. The apparatus of claim 4 further comprising: an additional secondary winding having one end coupled to said other end of said secondary winding; and   polarity switch means disposed between said switch means and said secondary winding for coupling said other one of said base microphone lines to a selected one of said secondary winding one end and said additional secondary winding other end.   
     
     
       8. The apparatus of claim 1 wherein said converter means comprises a transformer having primary and secondary windings, each end of said secondary winding connected to a respective one of said communications lines with one end of said secondary winding connected to said switch means and said secondary winding having a secondary winding tap connected to said switch means, said primary winding having a primary winding tap connected to one of said handset speaker lines and one of said base speaker lines, one end of said primary winding connected to the other one of said base speaker lines and said switch means, and said switch means when in said first position for, coupling one of said base microphone lines to one of said handset microphone lines, coupling said other one of said base speaker lines with the other one of said handset speaker lines, and coupling the other one of said base microphone lines with the other one of said handset microphone lines, and said switch means when in said second position for, coupling said one end of said secondary winding with said one of said base microphone lines, coupling said other one of said base speaker lines to said other one of said handset speaker lines, and coupling said secondary winding tap to said other one of said base microphone lines. 
     
     
       9. The apparatus of claim 8 further comprising signal level selector means disposed between said switch means and said secondary winding one end for selectively electrically resistively coupling said one of said base microphone lines to said secondary winding one end. 
     
     
       10. The apparatus of claim 8 further comprising polarity switch means coupled to said primary winding and said other one of said base speaker lines for coupling said other one of said base speaker lines and said switch means to a selected primary winding end. 
     
     
       11. The apparatus of claim 8 further comprising polarity switch means coupled to said secondary winding and said one of said base microphone lines for selectively coupling said one of said base microphone lines to a selected secondary winding end. 
     
     
       12. An apparatus for selectively coupling a telecommunications device having a pair of communication lines and a telephone handset having a pair of handset microphone lines and a pair of handset speaker lines to a telephone base at corresponding pairs of base microphone and speaker lines, said apparatus comprising: mode switch means selectable between a voice position and a data position for, when in said voice position, electrically coupling said handset microphone and speaker lines with said respective base microphone and speaker lines;   converter means coupled to said switch means for electrically interfacing said communications lines with said base microphone and speaker lines, said mode switch means for when in said data position electrically coupling said communications lines, said base microphone lines and said base speaker lines to said converter means, said converter means for inductively coupling a first signal on said communications lines to said base microphone lines and for directly coupling a second signal on said base speaker lines to said communications lines, said converter means further for electrically isolating said base microphone lines from said base speaker lines.   
     
     
       13. The apparatus of claim 12 further comprising signal level selector means coupled to said converter means means for, when said mode switch means is in said data position, providing a selected resistance into one of said base microphone lines. 
     
     
       14. The apparatus of claim 12 further comprising current source means coupled to said converter means for providing a current to said communication lines. 
     
     
       15. The apparatus of claim 12 wherein said converter means comprises a transformer having first and second electromagnetically coupled windings, each end of said first winding connected to a respective one of said communications lines, said first winding having a tap connected to one of said handset speaker lines and one of said base speaker lines, one end of said first winding connected to the other one of said base speaker lines and said mode switch means, one end of said second winding connected to said mode switch means, and the other end of said second winding connected to said mode switch means, coupling one of said base microphone lines to one of said handset microphone lines, said mode switch means when in said voice position for, coupling said first winding one end to the other one of said handset speaker lines, coupling the other one of said base microphone lines to the other one of said handset microphone lines, and said switch means when in said second position for, coupling said second winding other end to said one of said base microphone lines, resistively coupling said first winding one end to said other one of said handset speaker lines, coupling said second winding one end to one the other one of said base microphone lines. 
     
     
       16. The apparatus of claim 13 wherein said converter means comprises a transformer having first and second electromagnetically coupled windings, each end of said first winding connected to a respective one of said communications lines, said first winding having a tap connected to one of said handset speaker lines and one of said base speaker lines, one end of said first winding connected to the other one of said base speaker lines and said mode switch means, one end of said second winding connected to said mode switch means, and the other end of said second winding connected to said mode switch means, coupling one of said base microphone lines to one of said handset microphone lines, said mode switch means when in said voice position for, coupling said first winding one end to the other one of said handset speaker lines, coupling the other one of said base microphone lines to the other one of said handset microphone lines, and said switch means when in said second position for, coupling said second winding other end to said one of said base microphone lines, resistively coupling said first winding one end to said other one of said handset speaker lines, coupling said second winding one end to one the other one of said base microphone lines. 
     
     
       17. The apparatus of claim 15 wherein said transformer second winding is tapped with said other one of said base microphone lines connected to said second winding tap. 
     
     
       18. The apparatus of claim 15 wherein said second winding one end is connected directly to said first plug for connection to said one of said base microphone lines and said second winding other end is connected directly to said other one of said base microphone lines. 
     
     
       19. The apparatus of claim 15 wherein said first winding one end is connected directly to said first jack for connection to said other one of said handset speaker lines. 
     
     
       20. The apparatus of claim 18 wherein a resistor is disposed between said first winding other end and said first jack connection of said other one of said handset speaker lines. 
     
     
       21. The apparatus of claim 12 wherein said converter means comprises a transformer having first and second electromagnetically coupled windings, each end of said second winding connected to a respective one of said communications lines with one end of said second winding connected to said mode with means and said second winding having a second winding tap connected to said mode switch means, said first winding having a first winding tap connected to one of said handset speaker lines and one of said base speaker lines, one end of said first winding connected to the other one of said base speaker lines and said switch means, and said mode switch means when in said voice position for, coupling one of said base microphone lines to one of said handset microphone lines, coupling said other one of said base speaker lines with the other one of said handset speaker lines, and coupling the other one of said base microphone lines with the other one of said handset microphone lines, and said mode switch means when in said data position for, coupling said one end of said second winding with said one of said base microphone lines, resistively coupling said other one of said base speaker lines to said other one of said handset speaker lines, and coupling said second winding tap to said other one of said base microphone lines. 
     
     
       22. The apparatus of claim 13 wherein said converter means comprises a transformer having first and second electromagnetically coupled windings, each end of said second winding connected to a respective one of said communications lines with one end of said second winding connected to said mode with means and said second winding having a second winding tap connected to said mode switch means, said first winding having a first winding tap connected to one of said handset speaker lines and one of said base speaker lines, one end of said first winding connected to the other one of said base speaker lines and said switch means, and said mode switch means when in said voice position for, coupling one of said base microphone lines to one of said handset microphone lines, coupling said other one of said base speaker lines with the other one of said handset speaker lines, and coupling the other one of said base microphone lines with the other one of said handset microphone lines, and said mode switch means when in said data position for, coupling said one end of said second winding with said one of said base microphone lines, resistively coupling said other one of said base speaker lines to said other one of said handset speaker lines, and coupling said second winding tap to said other one of said base microphone lines. 
     
     
       23. A circuit for coupling a telecommunications device having a pair of communication lines and a telephone handset having a pair of handset microphone lines and a pair of handset speaker lines to a telephone base at corresponding pairs of microphone and speaker lines, said circuit comprising: first inductive means for, coupling to said pair of communications lines and said pair of base speaker lines, receiving a first signal upon said pair of base speaker lines, amplifying said first signal, and transmitting said amplified first signal upon said pair of communications lines;   second inductive means for coupling to said pair of base microphone lines, said second inductive means electromagnetically coupled to said first inductive means, said first and second inductive means electrically isolating said pair of base speaker lines from said pair of base microphone lines, said first inductive means further for receiving a second signal on said communications lines and for electromagnetically coupling said second signal to said second inductive means, and said second inductive means for receiving said electromagnetically coupled second signal from said first inductive means and for transmitting said received electromagnetically coupled second signal upon said base microphone lines.   
     
     
       24. The circuit of claim 23 further comprising signal level selector means coupled to said second inductive means for selectively establishing the signal level in said second signal. 
     
     
       25. A circuit for coupling a telecommunications device, having a pair of communication lines, to a two-wire telephone line via a telephone set having a telephone handset and a a telephone base coupled by a pair of microphone lines and a pair of speaker lines, said circuit comprising: first and second inductive means electromagnetically coupled to one another, said first inductive means for coupling to said pair of speaker lines, for receiving a first signal upon said pair of speaker lines, and for electromagnetically coupling said first signal to said second inductive means, said second inductive means for, coupling to said pair of communications lines and said pair of microphone lines, receiving said electromagnetically coupled first signal, amplifying said electromagnetically coupled first signal, and transmitting said amplified first signal upon said pair of communications lines, and said second inductive means further for receiving a second   signal on pair of said communications lines and coupling said second signal upon said pair of base microphone lines.   
     
     
       26. The circuit of claim 25 further comprising signal level selector means coupled to said second inductive means for selectively establishing the signal level in said second signal.